Method of disinfecting hard surfaces



United States Patent 3,544,688 METHOD OF DISINFECTING HARD SURFACES Reginald L. Wakeman, 1830 Rittenhouse Square, Philadelphia, Pa. 19103 No Drawing. Original application Aug. 16, 1966, Ser. No. 572,683, now Patent No. 3,479,406, dated Nov. 18, 1969. Divided and this application Apr. 2, 1969, Ser. No. 812,896 The p0rti0n of the term of the patent subsequent to Nov. 15, 1983, has been disclaimed Int. Cl. A01n 9/20 US. Cl. 424329 1 Claim ABSTRACT OF THE DISCLOSURE A method of disinfecting hard surfaces which comprises applying thereto an aqueous solution of alkyl dimethyl pseudocuminyl ammonium chloride, wherein the alkyl contains 8 to 18 carbon atoms.

This is a division of co-pending application Ser. No. 572,683, filed Aug. 16, 1966 now issued as Patent No. 3,479,406, dated November 18, 1969.

This invention relates to crystalline, non-delinquescent compounds of high microbiocidal potency, but which are, nevertheless, highly soluble in water.

Most highly microbiocidal quaternary compounds are either liquids or are in the forms of gels or soft, viscous solids which tend to easily absorb atmospheric moisture and to deliquesce. There are some microbiocidal quaternaries that are available in powedered form but they are light, flutfy powders, like dust. These are difiicult to handle and package and are so easily carried by the air that they are irritating to the skin, eyes and mucous membranes of persons handling or using them. Some of the heretofore known powder quaternaries are salts of bromine and are, therefore, very costly.

Quaternary compounds have a wide field of application in the treatment of water systems such as in swimming pools, cooling towers, air-conditioners, paper-making, oil recovery, sterilization of drinking water for animals, etc. However, natural water supplies are often of the hard water type containing mineral salts. Many quaternary compounds which are effective in soft water are not nearly as effective in hard water because of the inhibition of the metal salts.

The compounds of the present invention overcome all of the aforementioned difficulties of prior quarternaries, in that the present compounds are crystalline, non-hygroscopic, yet extremely water soluble. They, furthermore, do not form dusts and are, therefore, easily handled, packaged and used without any ill effects on the body. In addition, they have been found to be highly efiective both in soft and hard water and, since they are slow to dissolve, they may be applied in predetermined dosage forms and permitted to leach out gradually. The crystalline nature of the material also permits ready compression into tablets or briquettes, which are usually the easiest and safest mode of packaging, storing and handling. In the crystalline form it may be easily mixed with other granular material that may serve as either a synergistic agent, a carrier or a diluent.

In accordance with the present invention, the compounds which achieve the above objectives are the alkyl dimethyl pesudocuminyl ammonium chlorides wherein the alkyl contains C to C carbon atoms.

The present compounds are prepared by reacting the particular alkyl dimethyl amine with trimethyl benzyl chloride that has been obtained by the chloromethylation of pseudocumene (1,2,4-trimethyl benzene).

It is highly important that the preparation of the compounds take place in the absence of water in order to obtain crystalline material having the aforementioned desirable characteristics.

The following example is illustrative of the present invention, but is not intended to serve as a limitation thereof:

EXAMPLE A round-bottom, three-necked flask, equipped with an agitator, reflux condenser and heater, was charged with 58 grams (0.255 mol) n-dodecyl dimethyl amine, 42.5 grams (0.25 mol) pseudocuminyl chloride and 250 grams acetone.

The pseudocuminyl chloride was derived from 1,2,4- trimethyl benzene by the well-known process of chloromethylation with formaldehyde and HCl, and was thereafter rectified.

The mixture was heated to the boiling point and then refluxed for a period of four hours, during which time it reacted to form the quaternary ammonium salt. On gradual cooling to 15 C., it crystallized and was filtered off to yield a yellowish crystalline mass. This mass was then further purified by two additional recrystallizations from acetone. The final yield was 68 grams (or 70% of the theoretical) of a n-dodecyl dimethyl pseudocuminyl chloride, in the form of sparkling white, free-flowing, nonhygroscopic crystals. This material was found to be readily and freely soluble in water to more than 50% by weight of the water.

The product produced in the above manner assayed 99.5 pure, containing 0.97% water, as determined by the Karl Fischer method, and melted at 166l68 C.

Instead of acetone, other non-aqueous solvents can be used, as for example, methyl, ethyl or isopropyl alcohol, proplyene glycol, dioxane, dimethyl formamide, dimethyl sulfoxide, or any other feasible non-aqueous solvent.

The compound prepared in the above manner was tested biocidally by means of the Association of Ofiicial Agricultural Chemists Use-Dilution Method, indicative of actual disinfiection use levels for hard surfaces (this being the prescribed, standard regulatory test procedure) against Staphylococcus aureus and Salmonella choleraesuis. It demonstrated perfect passing performance at 350' parts per million of the active quarternary.

The Association of Ofiicial Agricultural Chemists Germicidal and Detergent Sanitizers Method was also used. This determines the minimum concentration of germicide which can be permitted for use in sanitizing hard, non-porous surfaces, and also determines the maximum water-hardness tolerances for recommended concentrations. According to this test, at 200 parts per million concentration, the product demonstrated good germicidal performance in the presence of water that contained magnesium and calcium at 600 parts per million hardness measured as CaCO Although normal dodecyl dimethyl pseudocuminyl ammonium chloride has been illustrated above, it is to be understood that all alkyl dimethyl pseudocuminyl ammonium chlorides wherein the alkyl contains from 8 to 18 carbon atoms, may be prepared in the same manner and are efiective generally for the same purposes.

Obviously, many modifications of the present inven- 10 The invention claimed is:

1. A method of disinfecting hard surfaces which com.- prises applying thereto a germicidal amount of an aqueous solution of crystalline alkyl dimethyl pseudocuminyl ammonium chloride wherein the alkyl has 8 to 18 carbon atoms.

References Cited UNITED STATES PATENTS 3,285,959 11/1966 McFarlane 260567.6

ALBERT T. MEYERS, Primary Examiner F. E. WADDELL, Assistant Examiner 

